1. Field of the Invention
The present invention relates in general to a tuning apparatus for a television system and a method of controlling the same, and more particularly to a tuning apparatus for a television system utilizing a rotary encoder, instead of a rotary switch and a remote controller, and a method of controlling the same.
2. Description of the Prior Art
With reference to FIG. 1, there is shown a front view of a conventional television set with a tuning apparatus of the rotary type. As shown in this drawing, the television set comprises a very high frequency (VHF) channel indicator 1, a VHF channel selector 2, a VHF channel fine tuning adjusting knob 3, an ultra high frequency (UHF) channel indicator 4, an UHF channel selector 5, an UHF channel fine tuning adjusting knob 6, a power switch and volume adjusting switch 7, and a control part 8 for controlling color, tint, brightness, and contrast, each being disposed on an external panel.
As shown in FIG. 1, the conventional television set with the tuning apparatus of the rotary type comprises separate components for selecting the VHF and UHF channels and separate components for adjusting fine tuning of the VHF and UHF channels.
FIG. 2 is a block diagram of a conventional television system with a tuning apparatus of the rotary type and the remote control type. The illustrated system comprises a key matrix unit 9 for outputting an electric signal of a desired level corresponding to VHF and UHF channels in accordance with a selection by the user, a remote controller 10 for outputting a remote radio signal corresponding to each channel in accordance with the selection of the user, a remote signal receiver 10a for receiving the remote radio signal from the remote controller 10 and amplifying the received signal by a predetermined amplification factor, a microcomputer 12 for controlling channel increment and decrement and channel selection of response to output signals from the key matrix unit 9 and the remote signal receiver 10a, a mechanical rotary knob 11 including a plurality of mechanical contacts, for outputting a channel select signal in accordance with a selection by the user, a tuner 13 for selectively outputting a broadcasting signal received through an antenna ANT in accordance with an output signal from the microcomputer 12 or an output signal from the mechanical rotary knob 11, an intermediate frequency (IF) processor 14 for IF-processing an output signal from the tuner 13, a detector 15 for detecting a desired composite video signal from an output signal from the IF processor 14, an audio processor 16 for processing only audio signals of an output signal from the detector 15 and outputting the processed audio signal through a speaker 19, and a video processor 17 for processing only the video signal of the output signal from the detector 15 and outputting the processed video signal through a CRT 18. Herein, the block designated by the reference numeral 20 corresponds to the construction of the television system with the tuning apparatus of the rotary type and the block designated by the reference numeral 21 corresponds to the construction of the television system with the tuning apparatus of the remote control type.
The operation of the conventional television systems with the tuning apparatus of the rotary type and the remote control type which is constructed as mentioned above will now be described.
First, if the operation of the conventional television system with the tuning apparatus of the remote control type will be described.
As shown in FIG. 4, if the user selects a desired channel by the key matrix unit 9 or the remote controller 10 when the television system is powered on, a channel select signal is inputted to the microcomputer 12. As a result, a channel number corresponding to the channel select signal is displayed by a display (not shown) under control of the microcomputer 12, Simultaneously, the tuner 13 outputs the broadcasting signal through an antenna ANT corresponding to the selected channel under another control of the microcomputer 12. The broadcasting signal outputted from the tuner 13 is applied to the audio processor 16 and the video processor 17 via the IF processor 14 and the detector 15. The audio processor processes only the audio signal of the received broadcasting signal and outputs the processed audio signal through the speaker 19. The video processor 17 processes only the video signal of the received broadcasting signal and outputs the processed video signal to the CRT 18.
If the user pushes a channel number key or a channel increment/decrement key of the key matrix unit 9 or the remote controller 10 to select a desired channel, the microcomputer 12 discriminates whether the key signal is a channel change signal. If the key signal is the channel change signal, the microcomputer 12 outputs a control signal for the change of channel to the tuner 13. Otherwise, if the key signal is not the channel change signal the microcomputer 12 outputs a control signal corresponding to the original channel to the tuner 13.
In this manner, in the conventional television system with the tuning apparatus of the remote control type, the channel selection and change are performed by pushing the channel number key or the channel increment/decrement key of the key matrix unit 9 or the remote controller 10 in accordance with a selection of the user.
As shown in FIG. 2 in the conventional television system with the tuning apparatus of the rotary type, a selection of broadcasting channel signals with different frequencies is performed by the rotation of the mechanical rotary knob 11 by the user. In this case, the tuner 13 includes a plurality of fixed resistors and a plurality of condensers, and a variable condenser for fine tuning the selected channel.
The user can select a broadcasting signal corresponding to a desired channel by rotating the mechanical rotary knob 11. The process of selecting the broadcasting signal is the same as that of the remote control type as mentioned above and the description thereof will thus be omitted.
However, conventional television systems with the tuning apparatus of the rotary type and the remote control type have the following disadvantages.
First, in the conventional television system with the tuning apparatus of the rotary type, the mechanical rotary knob includes a plurality of mechanical contacts, which requires a fair amount of physical strength by the user in order to rotate. Also trouble with the mechanical contacts may occur after a long period of operation. The trouble with the mechanical contacts is malfunction caused by the mechanical rotary knob. Also, because there is a wide difference between natural center frequencies of the VHF and UHF channels, there must be provided separate VHF and UHF channel selectors, resulting in an inconvenience due to separate channel selections.
Second, in the conventional television system with the tuning apparatus of the remote control type, it is inconvenient for some users to memorize all the broadcasting channel numbers in several districts. Also, selecting a desired channel by the channel increment/decrement key requires a large number of repetitions. Further, in the case where the use of the system is complex, some users may have difficulty operating the system.
Third, the conventional television system with the tuning apparatus of the rotary type has another disadvantage, in that its mechanical rotary knob requires a large volume of space, although it is more convenient than that of the remote control type because of simplicity of use in channel selection. The large volume of space needed by the mechanical rotary knob results in a large possessing area within the television system and results in manufacturing complexity. Also, the mechanical rotary knob is expensive.
Fourth, in the conventional television system with the tuning apparatus of the remote control type, there is present one input signal to the microcomputer. For this reason, noise accompanying the input signal results in malfunction of the microcomputer.